This is a study on nitric oxide synthesis and release by nerve cells (NIE cells,PC12W) when specifically stimulated with interferon, angiotensin, NMDA, or KCl +CaCl2. N-methyl-D-glutamine is used for the trapping of NO. EPR study is done on X-band using flat cell as sample holder. The pathway of NO synthesis will be confirmed by using arginine-free medium for culturing the relevant cells in addition to histochemical staining of cultured cells which show positive release of NO by EPR study when appropriately stimulated. Molecular biology and immunological methods were being used to fully understand the metabolic pathways of NO synthesis, with special reference to the receptors involved. It is a continuing project--one paper has been published, and an additional paper will be submitted when all the molecular and immunological data are completed.